Research On Reconstruction Algorithm Of Surface Structure Of Industrial-grade Products

With the arrival of the new industrial revolution,the development of industrial-grade product manufacturing urgently needs more efficient and accurate 3D measurement technology,and binocular structured light 3D measurement technology is more and more widely used in industrial product measurement.However,the accuracy of binocular structured light is limited by the accuracy of phase unwrapping,and when the morphology structure of the complex object to be tested,due to the limitation of the binocular cameras vision,can lead to the three-dimensional point cloud data is lack.Therefore,improving the accuracy of binocular structured light 3D measurement has important research significance and application value.The main contents of the thesis are as follows:1.The camera geometric model is established and the mapping relationship between 3D space points and 2D image plane is studied.The basic principle of binocular stereo vision is studied,including the establishment of binocular stereo vision model,calibration of binocular vision,epipolar geometry constraint and the stereo correction theory of the binocular camera.The advantages and disadvantages of each measurement method in 3D structured light measurement technology are analyzed from efficiency and accuracy.As the research direction of 3D structured light measurement technology in this thesis,the basic principles and calculation process of PMP(Phase Measurement Profilometry)and multi-frequency heterodyne method are derived in detail.2.Aiming at the nonlinear response of projection equipment and the error caused by multi-frequency heterodyne in 3D measurement system of binocular structured light,double N-step PMP based on multi-frequency heterodyne principle was proposed.By optimizing the projection fringe of the phase unwrapping method based on the multi-frequency heterodyne principle and combining it with the double n-step PMP,this method can effectively suppress the error in phase unwrapping.This method can also reduce the phase error caused by non-sinusoidal in fringe projection profilometry and improve the accuracy of 3D measurement.The validity and feasibility of this method are verified by phase unwrapping experiment and physical measurement.The phase accuracy obtained by phase unwrapping is improved obviously,and better measurement results are obtained.3.In order to solve the problem that the field of vision is blocked by binocular structured light in 3D reconstruction of complex objects,3D measurement technology of large field of binocular vision structured light on dual system is proposed.In this method,the binocular structured light system is regarded as two cameras sharing a projector,constituting two monocular vision subsystems.The 3D coordinate origin of the two subsystems is established at the same position,which avoids the complicated operation of 3D point cloud splicing,and on this basis,the point cloud information of camera blind area can be obtained.